Canberra maintains its policy prevents deaths at sea and discourages people smugglers but the tough immigration policy has been widely criticised.

The centre on Nauru has been dogged by allegations of widespread abuse and trauma among children and women. The president of the Australian Medical Association, Tony Bartone, recently described the situation for children there as "a humanitarian emergency requiring urgent intervention".

"The Nauruan government informed Médecins Sans Frontières/Doctors Without Borders that our services were 'no longer required' and requested that our activities cease within 24 hours," an MSF statement said.

Image copyrightGetty ImagesImage caption
Nauru is a tiny island in the Pacific, north-east of Australia

The charity said it was "extremely concerned that the health of our patients may be affected by this decision and urge the authorities to grant us permission to continue our lifesaving work".

Earlier this year, a group of human rights organisations demanded the Australian government remove all child asylum seekers held on Nauru.

The coalition of more than 30 charities and advocacy groups, including World Vision Australia and Oxfam Australia, wants all children moved to Australia or settled in a safe country elsewhere.